Sensitive and selective detection of chemical and biological analytes has important implications for medical and environmental testing and research. Hospitals and laboratories, for example, routinely test biological samples to detect potentially toxic substances, such as mercury and silver, in heavy metal poisoning diagnosis. Similarly, measurement of biomolecules, such as nucleic acids, is a foundation of modern medicine and is used in medical research, diagnostics, therapy and drug development.
Nanopore sequencing technology is a conventional method of detecting nucleic acid molecules. The concept of nanopore sequencing utilizes a nanopore aperture, which is a small hole or pore that extends transversely through a lipid bilayer membrane, i.e., through the depth or thickness dimension of the membrane. Nanopore sequencing involves causing a nucleotide to travel through a nanopore in the membrane, i.e., to travel between the top surface and the bottom surface of the membrane along the depth or thickness dimension of the membrane. A potential difference may be applied across the depth or thickness dimension of the membrane to force the nucleotide to travel through the nanopore. Physical changes in the environment of the nucleotide (for example, electric current passing through the nanopore) are detected as the nucleotide traverses through the nanopore. Based on the detected changes in the electrical current, the nucleotide may be identified and sequenced.
Areas for improving and broadening the scope of conventional systems and techniques of mercury detection have been identified, and technical solutions have been implemented in exemplary embodiments.